The mission of the Hormone &Metabolite Core is to assist investigators by performing uniform and standardized assays of various plasma metabolites, hormones, adipokines and cytokines in rodent models and human studies related to the regulation of obesity and co-morbidities, energy balance, eating disorders and nutrition related problems. The assay services provided within this Core provide an integrative framework for understanding obesity and associated disorders in glucose and lipid metabolism. In addition, the data obtained directly relate to and integrate with the analyses performed in the Body Composition, Animal Energy Balance Phenotyping, the Adipocyte and the Molecular Genetic Cores ofthe Center. The services provided at the HMC are best based in a Core Laboratory because they require special instrumentation and methodology, which would be difficult or impracticably expensive to establish in the laboratories of the individual investigators who are Members ofthe NYONRC.